This invention relates to automated classification systems for group technology applications, and in particular to a codeless classification system that provides a flexible method of defining unique attributes for a specific class of entity enabling the user to query on the attribute values.
Group technology is a loosely bounded manufacturing philosophy that exploits similarities in parts for efficiency in design and manufacture. It has evolved from parts classification and coding systems that were developed for engineering design retrieval. Parts may also be classified and coded by process, tooling, set up, or any other useful feature set. Companies using group technology principles have found that it can be applied to other business functions, including marketing, purchasing, cost accounting, materials control, and customer service.
Group technology is most commonly used for parts (or items) classification. An objective of parts classification is to provide a system to classify and locate parts with similar attributes. It helps to eliminate duplicate parts with different part numbers and avoids complete redesign of parts that are very similar. Virtually all group technology implementations use computer assisted classification coding as a method of defining families of similar parts within the manufacturing enterprise. A parts classification code is a string of characters, usually digits, that specifies the design and/or manufacturing attributes of the part. Many such coding systems are commercially available.
Currently, all parts classification systems use a fixed format code that identifies specific attributes of a part in a predefined schema. The code may be intelligible to the user or machine readable only, but its format is fixed at the time the code is generated. If the schema has multiple hierarchical levels, they are reflected in the code format.
The fixed format code creates problems with maintenance as a company and its classification system change over time. There may be some room in the existing format for minor additions to existing codes, but generally any significant maintenance to the classification schema will require a time consuming reclassification of all parts. As parts classification codes are used more extensively for such group technology applications as computer aided process planning, there will be increased maintenance to the classification schema.
Current automated methods of classification systems for group technology are limited to assigning classification codes to manufactured parts or other business entities and processes. The assigned codes are then used for query purposes. General purpose query tools are inefficient for classification queries. Special purpose programs to improve the performance result in preplanned classification queries which are inflexible. A query system for classification queries that is both flexible and yields high performance is not commercially available.
Thus, there exists a need for a codeless classification system that removes the hierarchical code from the parts data, thus avoiding the time-consuming reclassification that is necessitated when the code hierarchy changes. Furthermore, there is a need for a codeless classification system which enables definition of unique attributes for a specific class of entity and allows queries on the attribute values.